The prevalence of calcification around odontoid process and the incidence of crowned dens syndrome in the neurosurgical ward: A single institution's analysis

Objective: The objective of this study is to assess the prevalence and natural history of odontoid calcification and to identify factors related to its progression to crowned dens syndrome (CDS). Methods: We reviewed a consecutive series of patients who underwent head CT upon admission to the neurosurgical ward of Niigata Prefectural Shibata Hospital. We evaluated the relationship between the presence of odontoid calcification and the patient's age, sex, and primary disorder for admission. The incidence of CDS was also determined, and factors related to the progression of odontoid calcification to CDS were analyzed. Results: Odontoid calcifications were found in 88 out of 554 patients (15.9%) undergoing CT scans. Age, female, and stroke were predictive of odontoid calcification. The odds ratios (95% CIs) for age, female, and stroke estimated from the logistic analysis were 1.084 (1.054-1.114; p < .0001), 1.746 (1.06-2.875; p = .029), and 1.909 (1.123-3.247; p = .017), respectively. Eleven (12.5%) of the 88 patients with odontoid calcification developed CDS. The age, sex, and primary disorder for admission were not associated with the onset of CDS. Conclusions: Odontoid calcification is observed incidentally on head CT. Clinicians should keep in mind that patients with odontoid calcification might develop CDS, even if they are asymptomatic at the time of CT examination.